1. Field of the Invention
This invention relates generally to digital subscriber line (DSL) systems and relates more particularly to a system and method for fault isolation for DSL loop extenders.
2. Description of the Background Art
DSL loop extender technology can be used to increase DSL data rates for subscribers that are located well beyond the normal service limit for DSL, normally about 18,000 feet. Loop extenders can be installed at certain points along a subscriber loop to facilitate multi-mega bit DSL service at 30,000 feet or more. For best results, one or more loop extenders are installed along a long loop.
It is generally desirable that loop extenders be highly reliable and that malfunctioning devices be simply, quickly, and accurately identified. Indeed, it is desirable for loop extender diagnostic systems and methods to provide quick and accurate diagnostic results with low cost.
Hence, a need exits for diagnostic equipment and methodology with low complexity and high effectiveness. It is undesirable to add significant complex diagnostic circuitry into the loop extenders that may itself have a high likelihood of failure. It is also undesirable to include diagnostic procedures that are difficult to administer, produce ambiguous results, or that do not adequately test the equipment in question.
A further need exits for loop extender diagnostic procedures that may be administered completely from a central office, require little training, use equipment that is familiar to telephone company technicians, test a large portion of the circuitry of the device under test, accurately locate the malfunctioning device, and take little time.